Stitch-forming mechanism for sewing machines



May 28, 1929. V- 1 slGQDA 1,714-928x STITCH FORMING MECHANISM FOR SEWING MACHINES Filed June 25, i926 Snom/tfno@ Patented May 28, 1929.

UNITD saires` 1314,925 ./PATE oFFicE..

ITIGTOR il'. SIGODA, 0F BROQKLYN,l NEW` YORK.

` STITCH-Foaming MECHANISM Foa SEWING MACHINES.

'Application led June 23 tion with this needle, suitable means arearranged above and below the line of feed of the material for moving the latch element to open and closed positions respectively.

It is a further general object of my invention to provide a stitch formingmechanism for sewing machines which is relatively simplein its construction, positive and' reliable in practical operation andl may be readily applied td) various types ofsewing machines now in general use.l f X- With the above andother objects in view, the invention consists in the improved stitch forming mechanism and in the form, construction and relative arrangement of its several -parts as will be hereinafter more fully described, illustrated in the accompanying-drawings, and subsequently incorporated in the subjoined claim.

In the accompanying drawings, wherein I have illustrated one practical and satisfactory embodiment of the invention andl in which similar reference characters designate corresponding parts throughout the several views, I

` Figure 1 is a sectional view through the .bed plate of a .sewing machine illustrating a conventional type of material feeding mechanismand showingr my new stitch forminghmechanis'min cooperative relation therewit .2

Figs.- 2, 3, 4 yand 5 are detail views illustrating the' different positions of the two reciprocating needles in* the successive Stitches of forming the chain stitches;

Figs. 6 and 7 are-detail fragmentary elevations of the loo forming needle showing the pivoted latch e ements in closed and open lpositions respectively, and Y `Fig. 8 is a fragmentary view' of a portion of material illustrating the chain stitches 1926. sex-iai No. 117,960.

as formed by means of my present invention; For .purposes of illustration, Il have shown a section of the bed plate 5 A of a sewing machine having the vusual throat plate beneath which there is arranged any approved type of material feeding mechanism gener-l ally indicated at,6 and which is preferably enclosed or housed within a suitable casing 7 depending from'the under side of the bed plate. The mechanism 6' feeds the material indicated at.8 in astep by step movement longitudinally over the surface of the bed plate beneath the presser foot indicatedat 9.

Asher'ein shown, this presser foot at one of its ends hasI a pivotal connection withv a l rod-10 yieldably supported for reciprocating movement in a suitable bracket 11.l l

` The improved stitch forming mechanism constituting the subject matter of the pres- 'ent application includes a thread carrying needle 12 suitably secured lin the lower end`r 'of a needle bar 13 mounted to reciprocatel in the bracket 11 and actuated by any conventional type of mechanism now commonly employed for this purpose. The needle l12 pointed end through "whichithe thread indicated at T is drawn.` t

The loop forming needle 15 is arranged in cooperative relation withA the thread carrying needle 12 and is suitably fixed .in the lower end of a second reciprocatory needle bar 16 connected with a suitable actuating mechanism, said needle bar reciprocating in f needles are arranged in a vertical plane parallel with the line of movement of the material 8, but it will be understood that this is not an essential requisite and that the needles might be otherwise arranged if desired.

is of the usual type having an eye 14C-atl its i v The loop forming needle has a tapered or pointed end 18 to penetrate the materialV and at the inner end of the point and at one side thereof a notch or hook 19 is formed. The shank of the needle adjacent this vhook is slotted or recessed as at 20 and in said slot one end of a latch element 21 is pivotof the needle 12.

stud 25 is suitably mounted and lixed in posi-f tion beneath the bed plate 5.

In the operation of the mechanism above described,- the needles are simultaneously reciprocated in the same directions so that they penetrate the material 8 approximately at the same time during the period of rest of the material. When at the limit of their upward movement, it 'will be observed that the latch element or tongue 21 of theloop forming needle is positioned above the pin 24. Therefore, in the downward movement of said needle the pin engages the free end of said latch element and moves the same to its open position as shown in Fig. 7 of the drawings, said pin holding the tongue in open position until the point of the needle has penetrated. the material 8, said element being thereafter held in open position until it passes below the material 8 and below the pin 25. The thread carrying needle 12in its downward movement from the position,

shown in Fig. 2 to the position shown in Fig. 3 carries the thread through and below the material. The end of the needle'p15 at the same time passes between the thread and one side of the needle 12` in intersecting ,relation'with the latter until the hook 19 is below the thread, passing through the `eye needle 15 catches the thread below the material and forms a loop therein, and as the needle 15 moves upwardly, pin`25 engages the latch element 24 and moves the same to its closed position to retain the thread loop inthe hook of the needle. The loop is thus drawn upwardly until the latch element- 21 is againpositioned above the pin 24. As the material 8 is now fed in the di-v rection indicated by the arrow in Fig. 4 of the drawings, the threadloop is laid down upon the surface of the mateiial asthe needles 12 and 15 again start their downward movement and the needle 12 "passes through the loop thus formed, it being understood that the latch element 21 is moved to open position b the pin 24 to release the loop from the hoo 19. The hook then again engages the thread carried in needle 12 to yThe needles are then, moved upwardly so that the hook 19 of the form a second loopgtherein and pull the same upwardly through the material and through the end of the iirst loop. The described operations continue to form the chain stitching as illustrated in Fig. 81of the drawings. i f

From the foregoing description considered in connection with the accompany.-

Aing drawings, it is believed that the manner of operation of my improved stitch forming mechanism will be clearly understood. It will be seen that by the provision of the special loop forming needle as shown'in detail in Figs. 6 and 7 ot the drawings, the

two reciprocating needles will cooperate in a positive and reliable manner to accurately fermthe chain stitches. It will be apparent that this new needle mechanism constituting the essential part ot the stitch forming means of the sewing machine can be readily applied to various different types ot sewing machinesl new in general use without` necessitating any material alterations in the construction thereof. Alsoas above noted, thel mounting and `arrangement, of these needles as illustrated in the accompanying drawing is merely suggestive and other possible arrangements thereof' may be adopted in the applicationv of the invention to a articular type .of sewing machine.- There ore, while I have herein shown and described one simple and'satisfactory lembodiment of my present improvements. it is nevertheless to be understood that various modifications in the form, proportion and relative arrangement of the several parts may be resorted to without departing from the spirit and scope ot the invention as claimed.

I claim: l In a stitch forming mechanism for sewing machines, the combination of a looptorming needle having a hook at its end, an

eyeletted thread-carrying needle, the two needles being mounted to reciprocate oblliquely with respect to each otherand to cross each other after passing through the material to be stitched, the loo -forming needle havinga pivoted latch ad]acent the hook to close the hook and open same, and a pair of studs, one on one side et said material and the other o n the opposite side, in position -for the stud on the side of said material where the needles cross to engage said latch so that it closes the hook at the beginning of the return stroke of the loopforming needle, and tor the remaining stud to actuate the latch so that the hook is.

opened upon the beginning of the next forward stroke of said needles.

Intestimony that I claim the foregoing as my invention, I have signed my name hereto.

VICTOR J. SIGODA. 

